If you need to send email messages using an e-mail address with your own domain, make sure that the provider will provide you with usage of their SMTP server. The latter is the software system enabling email messages to be dispatched. SMTP is an acronym for Simple Mail Transfer Protocol and it manages all outgoing email messages from apps, webmail and contact forms. Every time a message is sent, the SMTP server checks with all the DNS servers throughout the world where the emails for the receiving domain are managed and once it acquires this info, it will connect to the remote POP/IMAP server to find out if the recipient mailbox is out there. In case it does, the SMTP server directs the e-mail body and so the receiving server sends it to the mailbox in which the recipient can open it and read it. Without an SMTP server on your server, you won't be allowed to send out e-mails at all.